Storage tanks are widely used in the process industries to store liquids that are below their boiling point at atmospheric temperature (some tanks may be insulated and they may have heating or cooling coils to maintain the temperature of the liquid that they are storing). Typically, tanks are either open to the atmosphere or to a system such as a flare or vent header that is at atmospheric pressure (this does not apply to floating roof tanks). Unlike pressure vessels, storage tanks cannot handle either high pressure or vacuum conditions.
Safety Moment #57: Equipment Spacing (Pumps/Fireproofed Pipe Racks) described the layout of pumps in a process or energy facility. Continuing the discussion, this Safety Moment describes some of the issues to be considered with regard to the layout of storage tanks, sometimes referred to as “API Tanks”.